Clinical features of tuberculosis among adults in sub-Saharan Africa in the 21st century.

Although tuberculosis was unknown in sub-Saharan Africa before the 19th century, rapid spread of infections due to Mycobacterium tuberculosis occurred during the 20th century and could be found in up to 50% of the adult population by the 1950s. Owing to changes in age structure, rapid urbanization associated with overcrowding living conditions, increasing poverty and the HIV epidemic a 300-400% increase in tuberculosis cases and deaths has been reported from sub-Saharan Africa. Persons dually infected with HIV and tuberculosis may have active tuberculosis with typical or atypical clinical features and/or involving multiple organ systems. In addition, mycobacteraemia associated with non-specific clinical features is common among HIV-infected persons, especially if they are severely immunocompromised. Because of the atypical clinical features these patients are easily misdiagnosed and are therefore likely to die from what is otherwise a curable illness. Consequently there is a need to better characterize the clinical features of all forms of tuberculosis, especially in the presence of HIV infection.